Question

A bag of marbles has 3 red, 4 blue, and 5 white marbles in it. What is the probability of reaching in and selecting a blue marble? (without looking)

Answer 1

`P(B)=(1)/(3)`

Explanation:

The number of red marbles in the bag is;
`n(R)=3`.

The number of blue marbles in the bag is;
`n(B)=4`.

The number of white marbles in the bag is;
`n(W)=5`.

The total number of marbles in the bag is:
`n(S)=3+4+5=12`.

The probability of selecting a blue marble is
`P(B)=(n(B))/(n(S))`

We substitute the given information to obtain:

`P(B)=(4)/(12)`

We simplify to obtain:

`P(B)=(1)/(3)`